In a recent case before the Court of Appeal of Singapore, the doctrine of equivalents used in other jurisdictions has been found not to apply in Singapore.
The case, Lee Tat Cheng v Maka GPS Technologies Pte Ltd  SGCA 18, concerned a patent for an in-vehicle recording system which is automatically switched on upon detection of ignition and automatically switched off after a fixed interval, after detection of deceleration or impact. One issue on appeal pertained to the finding of non-infringement in the first-instance decision. The Appellant argued that the doctrine of equivalents, which was adopted in the recent decision of the UK Supreme Court in Actavis UK Limited and others v Eli Lilly and Company  UKSC 48 (“Actavis”), handed out after the first-instance decision, should be applied in Singapore. The Court of Appeal of Singapore rejected the argument based on several reasons.
1. Actavis approach is inconsistent with Singapore patent law
Firstly, the Court held that the approach set out in Actavis is inconsistent with Singapore patent law because it allows the extent of the protection conferred by a patent to go beyond the scope of the claims in the patent, when purposively construed. The Court noted that although Section 113 of the Singapore Patents Act, which defines the extent of the protection conferred by a patent, is materially similar to Section 125 of the UK Patents Act, the interpretation of the latter is governed by the Protocol on the Interpretation of Article 69 of the European Patent Convention (EPC). However, Singapore operates in a different legal framework from that of the EPC.
2. Patentee is bound by the language used to frame their patent claims
Further, the Court held that it is fair for a patentee to be bound by the language in which they choose to frame the claims of their patent. It had been established that the language of the claims is purposively construed, rather than in a literal way. The Court considered that the purposive approach struck the right balance between the need to afford fair protection to the patentee and the need to provide a reasonable degree of certainty to third parties. The Court was of the view that Actavis extends the scope of the protection conferred by a patent beyond its claims, and “tilts the balance too far in favour of the patentee and in a manner that is not compatible with the terms of the governing legislation”.
3. Purposive approach provides greater certainty
The Court also took the view that the application of Actavis may give rise to undue uncertainty. The Court noted that the purposive approach is aimed at determining what, based on the language of the claims, the patentee would have objectively meant to be the scope of the protection conferred by a patent at the time of the patent application. On the other hand, the doctrine of equivalents brings in an element of ex post facto analysis because it may be based on the knowledge at the date of the alleged infringement. The purposive approach was considered to provide greater certainty.
A significant decision
The ruling by the Court of Appeal of Singapore in this case is significant because it clarifies Singapore’s position in respect of the approach to be used when determining the scope of the protection conferred by a patent. In the absence of any legislative changes, the test remains “what would the words used in the patent claims convey to the notional skilled person at the date of the patent application?”.